JS1k: The JavaScript code golfing competition

with(document.body)style.background="#111",c=children[C=X=x=S=n=0];addEventListener('mousemove',function(L){x=L.clientX;y=L.clientY},0);c.width=w=innerWidth-15;c.height=y=Y=h=innerHeight-40;L=1;P={};X=Y=300;T=[];I=setInterval("with(c.getContext('2d'))with(Math){font='12px';r=random;clearRect(0,0,w,h);e=x-X;f=y-Y;X=min(X+e*.1,w);Y=min(Y+f*.1,h);T.push({a:X,b:Y});beginPath();strokeStyle='#699';for(O=0;O<T.length;O++){with(T[O])u=T[O+1],O==0?moveTo(a,b):u&&quadraticCurveTo(a,b,a+(u.a-a)/2,b+(u.b-b)/2),a-=1.3*L,b+=L;if(O>60)T.shift();}stroke();C+=L+sqrt(e*e+f*f)/99;for(O in P)with(P[O])a-=L*d,b+=L*d,M=X-a,N=Y-b,(a<0||b>h?1:0)||sqrt(M*M+N*N)<(S>0?16:3)+c&&(e?S=300:(S>0?C+=20:clearInterval(I)))?(delete P[O],n--):0,_e?'#0fc':'#f00'_a,b,c_p={a:r()*w,b:0,c:3+r()*4,d:2+r(),e:S--<1&&r()>.99?1:(n<L<<7?0:2)};if(r()>w/(w+h))p.a=w,p.b=h*r();if(p.e<2)n++,P[L]=p;if(S>99||S>0&&S%3>1)_'#066'_X,Y,17__'#9ff'_X,Y,4_fillText(C|0,9,15);}L+=.001".replace(/_([^_]+)_([^_]+)_/g,'fillStyle=$1,beginPath(),arc($2,0,PI*2,1),fill();'),42)

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/*
Sinuous, by Dmitri Gaskin and Hakim El Hattab.

Sinous is a simple game - move your player with the mouse, try to avoid the red
dots, and the green dots give you (temporary) invulnerability. Your score is in
the upper left hand corner.

---

Based on Hakim's Sinuous at http://www.hakim.se/experiments/html5/sinuous/01/
(vote for it at 10k apart: http://10k.aneventapart.com/Entry/83), with
permission.

---

The code is full of abbreviations - single letters instead of variable names.
These are all documented. Deal with it :-).

---

The code you see here is run through a custom minifier that brutally gets rid
of pretty much all whitespace.

*/

with (document.body)
  style.background = "#111",
  // Set the X (of the mouse and player) to 0, but set the Y to window height
  // so it starts at the bottom left (and the things come in from the top
  // right).
  c = children[C = X = x = S = n = 0];
  // c: canvas
  // C: score
  // X: current player X
  // x: mouse x
  // b: current boost
  // n: number of particles.

addEventListener('mousemove', function(L) {
  x = L.clientX;
  y = L.clientY
}, 0);


c.width = w = innerWidth - 15; // w: window width
c.height = y = Y = h = innerHeight - 40; // h: window height
  // Y: current player Y
  // y: mouse y

L = 1; // Advancement (place in the game)
P = {}; // Particles
X = Y = 300;
T = [];
I = setInterval(---
  with (c.getContext('2d'))
    with (Math) {
      font = '12px';
      r = random; // Just a quick shortcut.
      clearRect(0, 0, w, h); // Clear the whole screen.

      e = x - X; // Calculate x and y distance from mouse to point
      f = y - Y;
      X = min(X + e * .1, w); // Only go slowly towards the mouse.
      Y = min(Y + f * .1, h);
      
      T.push({a: X, b: Y});

      beginPath();
      strokeStyle = '#699';
      for (O = 0; O < T.length; O++) {
        with (T[O])
          u = T[O + 1],
          O == 0 ? moveTo(a, b) : u && quadraticCurveTo(a, b, a + (u.a - a) / 2, b + (u.b - b) / 2),
          a -= 1.3 * L,
          b += L;
        if (O > 60)
          T.shift();
      }
      stroke();

      C += L + sqrt(e * e + f * f) / 99; // Add to the score:
                                      // - A little but for staying alive.
                                      // - Delta - movement is encouraged.
      for (O in P)
        with (P[O])

        // Advance the int
        a -= L * d,
        b += L * d,

        // Find the distance between two ints [x,y] and [x,y] using the thagorean.
        M = X - a,
        N = Y - b,
        (a < 0 || b > h ? 1 : 0) || // Piggyback on - are we off the screen?
          sqrt(M * M + N * N) < (S > 0 ? 16 : 3) + c && // Collision
          (e ? S = 300 : (S > 0 ? C += 20 : clearInterval(I))) // If its a blue dot, put up the shield
                                                               // If it's a red dot and the sheld is up,
                                                               // Add to the score (and delete it).
                                                               // If the shield isn't up, end the game.
        ?
          (delete P[O], n--) : // Hide the dot (either blue or red with shield).
          0, // Do nothing, no collision, on the screen.

        // Draw the dot.
        _e ? '#0fc' : '#f00'_a, b, c_
      p = {
        a: r() * w, // X
        b: 0, // Y
        c: 3 + r() * 4, // Diameter
        d: 2 + r(), // Speed
        e: S-- < 1 && r() > .99 ? 1 : (n < L << 7 ? 0 : 2) // type: 0 = enemy, 1 = bonus, 2 = nothing.
                                                           // <<7 multiplies by 128 and saves a character
      };
      if (r() > w / (w + h))
        p.a = w,
        p.b = h * r();
      if (p.e < 2)
        n++,
        P[L] = p; // Evil evil evil: L goes up every round, so use that as
                  // the key.

      if (S > 99 || S > 0 && S % 3 > 1)
        _'#066'_X, Y, 17_
      _'#9ff'_X, Y, 4_

      fillText(C | 0, 9, 15); // Show the current score.
    }
    L += .001 // Advance the game, ever-so-slightly
---.replace(/_([^_]+)_([^_]+)_/g,'fillStyle=$1,beginPath(),arc($2,0,PI*2,1),fill();'), 42)